Control device for fuel injection pumps



S p 3, 1955 H. K. LINKS ET AL 2,717,587

CONTROL DEVICE FOR FUEL INJECTION PUMPS Filed May 25, 1951 2 Sheets-Sheet 1 ifiom 8/5 P 1955 H. K. LINKS ET AL ,717,587

CONTROL DEVICE FOR FUEL INJECTION PUMPS Filed May 25, 1951 2 Sheets-Sheet 2 g 18 Q l United States Patent Ofiice 2,717,587 Patented Sept. 13, 1955 CONTROL DEVICE FOR FUEL INEECTEON PUMPS Heinrich K. Links, Stuttgart, and Robert J. Wirsching,

Stuttgart-Unterturkheim, Germany, assignors to Daim- [er-Benz Aktiengesellschaft, Stuttgart-Unterturkheim, Germany Application May 25, 1951, Serial No. 228,192

Claims priority, application Germany May 25, 1950 17 Claims. (Cl. 12314 The present invention relates to a control device for fuel injection pumps of combustion engines with fuel injection. More particularly, the present invention relates to control devices for fuel injection pumps of combustion engines wherein an intermediate member is provided to obtain a control range as large as possible, which may eventually extend from the idling speed position to the full load position and in which the adjusting member is operative in response to the speed of the engine, on the one hand, and to the setting of a control member determining the quantity of fuel to be injected, on the other hand.

It is, accordingly, an object of the present invention to provide for adjustability of the control device for different control ranges which is constructed in as simple as possible a manner and which permits a control movement which is as frictionless as possible.

Accordingly, one feature of the present invention lies in the fact that for an additional adjustment of the intermediate member an adjustable stop or support is provided, against which the intermediate member tries to place itself under the action of a resilient means to overcome a controllable play, and by the adjustment of which the control device may be adjusted to different load ranges, for example, to an idling speed, or to a full load range.

It is a further object of the present invention to provide an adjusting device for limiting the quantity of fuel to be injected to a maximum value.

It is a further feature of the present invention to provide an adjustable full load stop for the control member controlling the fuel quantity.

A still further feature of the present invention lies in a provision of an intermediate member, which, dependent upon the position of the controlling device, is adjusted in such a way that with a stopping or starting speed of the engine it permits an adjustment to a position corresponding to an overload quantity of fuel, whereas during normal operation it prevents adjustment to such overload position. The quantity of fuel adjusted thereby is automatically increased when the engine is stopped, so that when the engine is started again, it is no longer necessary to change the adjustment of the fuel quantity to an overload position or to a position corresponding to the starting quantity.

It is a still further object of the present invention to provide a control device which makes it impossible for the driver to exceed the fixed, predetermined full load injection quantity by an arbitrary change during the drive.

Another object of the present invention is to provide a full load stop which is arranged in such a way, as for example, outside the linking point of the quantity control member with a lever serving as intermediate member, that with the lever supported against the full load stop, the quantity control member is changed when the speed control device is operated, whereby an exact assimilation of the full load quantity of the fuel dependent upon the pump speed is enabled.

It is a further object of the present invention to provide a control device which is compact and of small dimensional design, and which is capable to readily absorb advantageously the existing forces by a suitable connection of the drive.

Accordingly, a still further object of the present invention is the provision of a drive for the control device with an intermediate transmission so as to drive the control device from the drive shaft of the injection pump at a faster speed. This offers the advantage that the control device also offers suflicient working energy in the idling speed thereof without the centrifugal weights thereof being specially large of necessity.

It is still another object of the present invention to provide a friction coupling between the injection pump and the speed control, which is suitably arranged by an adjustable spring pressure, for example, at the end of the pump drive shaft. The torsional oscillations emanating, for example, from the crankshaft or from the cam shaft of the fuel engine, or from the cam shaft of the injection pump are efficiently absorbed thereby. Thus, unnecessary wear of the control rod is prevented, on the one hand, and particularly high accelerations and retardations are kept off from the control device, on the other hand which, because of theCoriolis forces, which arise therefrom, would have disturbing effects upon the operation of the control device.

Further features, objects and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawing which shows for purposes of illustration only one preferred embodiment, and wherein:

Figure 1 is a central longitudinal sectional view through the control device in accordance with the present invention;

Figure 2 is a cross-sectional view through the control device along line AB of Figure l;

Figure 3 is a sectional view of the full load adjusting lever along line'CD of Figure 2 and Figure 4 is a sectional view along line EF of Figure 1.

Referring now more particularly to the drawing wherein like reference numerals have been used throughout the various views to designate like parts, reference numeral 2 designates the control casing which is flanged to the casing 1 of the injection pump for the combustion engine. To provide for the drive of'the control device, a hub piece 4 is keyed to the end of the cam or drive shaft 3 of the injection pump. Gear 5 is arranged freely rotatable on hub piece 4. By means of an elastic lamella disk 6, gear 5 is pressed against collar 7 of hub piece 4, the pressure being determined by an adjustable nut 8 through a pressure piece 9. The pressure piece 9is at the same time formed as a cam or eccentric disk and drives over a knee lever 10 the pump piston 11 of the fuel delivery pump 12 placed in front of the injection pump. Piston 11 is pressed downwardly by a spring 13, whereby suction takes place during the downward stroke of the piston and pressure delivery during the upward stroke of the piston. A pressure valve 14 is arranged Within the piston 11.

The gear 5 located on the end of the pump drive shaft 3 is in engagement with a pinion-like gear 15 on control shaft 16. The transmission ratio of gears 5, 15 is chosen in such a way that the control device is driven by the pump drive shaft at a higher speed by a gearing up arrangement. It is made possible thereby to make the centrifugal weights 17 of the control device relatively small, with sufficient insensitiveness also in the lower speed ranges. v v

The control Weights 17 act on control sleeve 18 Which,- on the one side, is loaded by the full load springs 19,

20, which become effective only above a certain speed and, on the other side, by the spring 21 for the idling speed.

The control sleeve 18 is provided with bearing-like projections 22, in which axle shaft 23 is fixed. Axle shaft 23 serves as a bearing for the control lever consisting of two arms24, whose lower ends are connected with each other by a red-shaped bridge 26, while, near the upper ends thereof, arms 24 and 25 are connected by a pin 27 which, e. g., by the insertion of an adjustable link member 28, serves to connect the quantity control member 29, e. g., a control rack turning the pistons of the injection pumps.

The control sleeve 18 and the control lever 24, 25 are connected to each other by a torsional helical spring 30 in such a way that the spring tries to turn the control lever clockwise around its turning axle 23 as seen in Figure 1 against a control stop or abutment member 31 which, by means of an eccentric 32, may be displaced by an external control lever 33, actuated, e. g. by hand or by foot.

The adjusting range of stop or abutment member 31 is limited by stops 34 and 35, of which the first serves as maximum speed stop and the latter as an idling speed stop.

Above pin 27 a cam 36 is carried by inner control levers 24, 25 which may be turned by lever arm 37. Lever arm 37 is linked to a further arm 38 which in turn is supported on axle 23, itself fastened to the control sleeve 18, and whose lowerend 39 abuts against an eccentric stop 40 adjustably mounted in the casing 2. A torsional helical spring 41 couples the axle or shaft 23 with the lever 38 in such a way that lever 38 under spring pressure is constantly urged against eccentric stop 40, so that with a displacement of the control sleeve in the direction of the arrow x or y (Figure 3) lever 37 together with cam 36 is turned around axle 42. The-cam 36 engages an abutment member 43 against which cam 36 abuts in a manner to be more fully described hereinafter.

Furthermore, lever arm 44 is mounted on a shaft 45 supported in casing 2 which may be adjusted by a lever 46 from the outside thereof. The lever arm 44 may thereby place itself against a stop 47 provided on member 28 of the quantity control rods and thereby allowing the quantity control member 29 to be moved to its stop position against the eifect of the spring 30, when it is thus actuated by lever 44.

The manner of operation of the illustrated control device may be described as follows:

The external control lever 33 connected, e. g., with the accelerator, displaces the control stop 31 by means of eccentric 32 in such a way that it is brought into position 31' for full load and to the position 31" for idling speed indicated in Figure 1 in dotted lines, while the position of the stop in full lines shows the control stop in an intermediate position. The torsional helical spring 30 tries to turn the control lever 24, 25 clockwise, as seen in Figure 1 around axle 23 thereof, as already mentioned above, in such a way that cam 36 places itself against the stop or abutment member 43.

If now, e. g., lever 31 is brought to the full load position 31', a play s exists between the bridge-like stop 26 supported by control levers 24, 25 and between control stop or abutment member 31, depending on the prevailing speed. Control levers 24, 25 may then be displaced by an amount proportional to play s before stops 26, 31 reengage with each other. With an increase in speed and the following displacement of the control sleeve 18 to the left (direction of the arrow x) against the effect of the springs 19, 20 and 21, the control levers 24, 25, supported against the stop 43, will first turn to the left, as viewed in Figure 1, whereby the quantity control member 29 undertakes at first a small displacing movement to balance the speed, but in the main remains essentially undisplaced, while the torsion of helical spring 30 is lessened with stop 26 moving toward control stop 31. As soon as the stop 26 places itself against the control stop 31 (e. g., in the position 31'), the control levers 24, 25 will, with an increase in speed, turn around stop 26, whereby cam 36 disengages stop 43 and the quantity control member 29 is brought to the idling speed position, which means that the engine speed is reduced by the control device. This reduction will take place earlier or later depending on the position of lever 31. In the idling speed position 31", it takes place already at such an early moment that already with just exceeding the idling speed, the fuel quantity is reduced.

If, following the reduced quantity of fuel injection, which is caused by the above-described control, the speed decreases, the torsional helical spring 30 may again displace the quantity control member 29 so long in the direction of the full load position, until a balanced condition exists between the position of the external control lever 33, i. e., of the control stop 31 and the control sleeve 18. This condition corresponds to a certain desired speed. With all changes stemming from the side of the engine load which may affect the equilibrium, the quantity control member 29 is always displaced in such a way that the equilibrium is re-established.

Figure 3 shows the way of operation of the adjusting device for the full-load stop, whereby the position in full lines shows the operation at high speeds, while the dashed and dotted position indicates the operation at starting speeds. As may be seen, cam 36 is directed against the stop 43 at high speeds, in such a way that it keeps the pin 42 and therewith control levers 24, 25 at a maximum distance from stop 43, which means that it prevents the displacement thereof to an overload quantity, whereas with starting speeds the cam 36 is directed upwardly, as indicated in the position 36, and thus allows for change to an overload quantity by providing closer approach of pin 42 to stop 43 whereby control member 29 may be moved further to the right, as viewed in Figure 1, to provide for an overload quantity of fuel.

The present invention is not restricted to the illustrated embodiment, but may be varied at Will Within the scope of the ideas of the present invention as known by a person skilled in the art.

What we claim is:

1. A control device with a stationary part for fuel injection pumps of injection combustion engines, comprising a first control member operative in response to the rotational speed of the engine, a second control member for adjusting the quantity of fuel to be injected, an intermediate member connected between said first and said second control member to transmit the motion of said first control member to said second control member, a third control member, means for supporting said third control member in said stationary part at a distance from said first and said second control member within the field of motion of said intermediate member to provide a play between said third control member and said intermediatemember with said intermediate member in a position corresponding to a rotational speed of a lower range so that movement of said first control member in said lower range produces only a small movement of said second control member in the direction of reduction of the fuel quantity while overcoming said play and a larger movement of said second control member only upon change over to a rotational speed of a higher range after abutment of said intermediate member against said third control member, and means for varying the amount of play between said intermediate member and said third control member.

2. A control device according to claim 1, in combination with stop means co-operating with said intermediate member, and means for adjusting said stop means in response to the rotational speed to provide for adjustment of said second control member to a position corresponding to overload quantity only during starting rotational speeds and to prevent the adjustment of said second control member to said last-named position by said stop means during rotational speeds in said higher range.

I 3. A control device having a stationary part for fuel injection pumps of injection combustion engines comprising a first control member operative in response to the rotational speed of the engine, a second control member for adjusting the quantity of fuel to be injected, an intermediate member connected between said first control member and said second control member to transmit the adjusting movement of said first control member to said second control member, an abutment member for said intermediate member to arrest said intermediate member in a position corresponding to a predetermined maximum quantity of fuel to be injected, and a third adjustable control member located adjacent the end of said intermediate member on the side thereof opposite said second control member with respect to said first control member, means for adjustably supporting said third control member in said stationary part to provide for adjustable play between said third control member and said intermediate member, said third control member extending within the path of said intermediate member during adjusting movement thereof by said first control member and thereby effectively constituting a further adjustable abutment member for adjustment of said intermediate member in a direction opposite to said first-named abutment member to thereby effect abutment of said intermediate member against said third control member upon movement of said first control member at a varying rotational speed thereby disengaging said intermediate member from said firstnamed abutment member and adjusting said second control member to a position corresponding to a smaller quantity of fuel.

4. Control device according to claim 3, in combination with adjusting means operative in dependence on the rotational speed of the engine for adjusting said first-named abutment member to provide for adjustment of said second control member to a position corresponding to greater quantity of fuel to be injected with lower rotational speeds than with higher rotational speeds.

5. Control device according to claim 3, in which said first-named abutment member interferes with said intermediate member outside the point of connection thereof with said second control member in such a way that with an adjustment of said first control member caused by an increase in speed, said intermediate member abutted by said first-named abutment member adjusts said second control member to a position corresponding to a slightly decreased fuel quantity.

6. A control device for fuel injection pumps of injec tion combustion engines, comprising a relative stationary part, a speed governor, a control sleeve, means for adjusting said control sleeve by said speed governor in accordance with the engine speed, an intermediate member supported on said control sleeve, a control member for adjusting the amount of fuel to be injected, means for pivotally connecting said control member to said intermediate member, abutment means to provide an abutment for said intermediate member against said relatively stationary part in one direction of movement thereof, an adjusting member located within the field of movement of the end of said intermediate member opposite said abutment means outside the point of support of said intermediate member on said control sleeve, said adjusting member being spaced from said intermediate member to provide play therebetween, resilient means for urging said intermediate member into abutment with said relatively stationary part by the intermediary of said abutment means, and means for changing the amount of play to effect abutment of said intermediate member against said adjusting member upon movement of said control sleeve during varying speed of said engine thereby disengaging said intermediate member from said relatively stationary part against the action of said resilient means.

7. Control device according to claim 6 with means for adjusting said abutment means by said speed governor, whereby said control member for adjusting the amount of fuel may be adjusted to a larger fuel quantity with starting speeds than with higher speeds.

8. A control device according to claim 6, wherein said intermediate member consists of two double-armed single levers arranged on both sides of said control sleeve, a cross member connecting one end of each arm of said two single levers and cooperating with said adjusting member, and means for connecting the other ends of the arms of said two single levers for cooperation with said relatively stationary part by means of said abutment means, whereby the member controlling the fuel quantity is linked to said arms.

9. Control device according to claim 6 wherein said abutment means comprises a cam rotatably supported on said intermediate member near the pivotal connection thereof with the control member controlling the fuel quantity, and rods operated by said control sleeve to turn said cam in accordance with the position of said control sleeve so that said cam is turned out of the range of abutment with said relatively stationary part at starting speeds and is turned into said range with higher speeds, whereby said intermediate member is prevented from adjusting said member controlling the fuel quantity to an overload position at said higher speeds.

10. Control device according to claim 6 comprising an additional adjusting device projecting from said relatively stationary part for adjusting said member controlling the fuel quantity to a position corresponding to complete stoppage of fuel delivery.

11. The combination according to claim 6 wherein said adjusting member comprises a lever with an eccentric member for supporting said adjusting member, and an abutment member for said lever.

12. A control device according to claim 6, wherein said abutment means comprises a relatively stationary abutment member, a cam member cooperating with said abutment member rotatably supported on said intermediate member, a lever connected with said cam member, an additional lever cooperatively connected with said firstnamed lever, means for supporting said additional lever essentially on said control sleeve, a relatively stationary abutment member for said additional lever outside of said supporting means, said two levers cooperating with each other, and said cam member and said relatively stationary abutment member being operative so as to rotate said cam member upon movement of said control sleeve in the starting speed direction by abutment of said additional lever against said relatively stationary abutment member to enable said intermediate member to approach said abutment member and to adjust said fuel quantity control member to larger quantities of fuel while preventing, upon movement of said control sleeve in the opposite direction, such an approachment.

13. A control device according to claim 12, including means for adjusting said last-mentioned abutment member.

14. A control device according to claim 12, further comprising an adjustable eccentric for said last-mentioned abutment member.

15. A control device according to claim 12, wherein said abutment means for the second of the two last-mentioned levers comprises a trunnion simultaneously serving to support said intermediate member on said control sleeve.

16. A control device according to claim 12, wherein said intermediate member is provided with a pair of arms surrounding said control sleeve, and wherein said abutment means comprises a pair of arms on said control sleeve, a trunnion connecting said pair of arms and serving to support said two-armed intermediate lever, said trunnion being extended beyond the point of support of one arm and bearing on the extension thereof the second of said two last-mentioned levers.

17. A control device according to claim 6, wherein said intermediate member consists of two double-armed single levers located on both sides of said control sleeve, a cross member connecting one arm of each of said two single levers for cooperation with said adjusting member, and means for connecting the other arms of said two single levers for cooperation with said relatively stationary part by the intermediary of said abutment means, whereby the member controlling the fuel quantity is linked to said double-armed levers, said abutment means comprising a pair of arms, a trunnion connecting said two last-mentioned arms and simultaneously serving as support for 10 References Cited in the file of this patent UNITED STATES PATENTS Hogeman Oct. 21, 1941 Baierlein Apr. 28, 1942 

